Tsai S K, Huang S W, Lee T Y
Department of Anesthesiology, National Yang-Ming Medical College, Taipei, Taiwan, R.O. China.
Br J Anaesth. 1994 Jun;72(6):674-8. doi: 10.1093/bja/72.6.674.
In order to study the neuromuscular interactions between suxamethonium and magnesium sulphate (MgSO4), we have determined the dose-response relationship of suxamethonium and the neuromuscular actions of 1.25 x ED50 dose of suxamethonium, both before and after pretreatment with MgSO4. We have also compared the effect of 1.25 x ED50 dose of suxamethonium in the absence and in the presence of 50% neuromuscular block, established previously by infusion of MgSO4. Twenty-one cats were anaesthetized with urethane. Train-of-four stimulation was applied every 12 s to the sciatic nerve and the force of contraction of the tibialis anterior muscle was measured. The potency of suxamethonium decreased in each instance with pretreatment with MgSO4. The ED50 of suxamethonium increased significantly from mean 21.0 (SEM 1.9) micrograms kg-1 before MgSO4 to 25.6 (2.3) micrograms kg-1 after MgSO4 60 mg kg-1 and to 26.6 (2.2) micrograms kg-1 after MgSO4 90 mg kg-1 (P < 0.05). Twitch depression produced by 1.25 x ED50 dose of suxamethonium decreased significantly with MgSO4 pretreatment, from 76.7 (2.6)% before MgSO4 to 61.7 (6.4)% after MgSO4 60 mg kg-1 and 48.7 (7.5)% after MgSO4 90 mg kg-1 (P < 0.05). With stable 50% neuromuscular block, established previously by infusion of MgSO4, the 1.25 x ED50 dose of suxamethonium produced more twitch augmentation (133 (6.3)% vs 108.3 (1.3)%; P < 0.05) and less twitch depression (31.6 (9.6)% vs 74.1 (0.6)%, P < 0.05) than in the absence of MgSO4. The results of all three methods demonstrated that the pharmacological interaction between suxamethonium and magnesium was antagonistic.
为了研究琥珀酰胆碱与硫酸镁（MgSO4）之间的神经肌肉相互作用，我们测定了琥珀酰胆碱的剂量-反应关系以及在硫酸镁预处理前后，1.25倍半数有效剂量（ED50）的琥珀酰胆碱的神经肌肉作用。我们还比较了在预先通过输注硫酸镁建立50%神经肌肉阻滞和未建立阻滞的情况下，1.25倍ED50剂量的琥珀酰胆碱的作用。21只猫用氨基甲酸乙酯麻醉。每12秒对坐骨神经施加四个成串刺激，并测量胫前肌的收缩力。在每种情况下，用硫酸镁预处理后琥珀酰胆碱的效能均降低。琥珀酰胆碱的ED50从硫酸镁预处理前的平均21.0（标准误1.9）微克/千克显著增加到硫酸镁60毫克/千克预处理后的25.6（2.3）微克/千克，以及硫酸镁90毫克/千克预处理后的26.6（2.2）微克/千克（P<0.05）。1.25倍ED50剂量的琥珀酰胆碱引起的抽搐抑制在硫酸镁预处理后显著降低，从硫酸镁预处理前的76.7（2.6）%降至硫酸镁60毫克/千克预处理后的61.7（6.4）%和硫酸镁90毫克/千克预处理后的48.7（7.5）%（P<0.05）。在预先通过输注硫酸镁建立稳定的50%神经肌肉阻滞的情况下，1.25倍ED50剂量的琥珀酰胆碱产生的抽搐增强作用（133（6.3）%对108.3（1.3）%；P<0.05）比未用硫酸镁时更多，抽搐抑制作用（31.6（9.6）%对74.1（0.6）%，P<0.05）比未用硫酸镁时更少。所有三种方法的结果均表明，琥珀酰胆碱与镁之间的药理相互作用是拮抗的。
